He mentioned the Khawarij and said, "Among them is a man with a deformed hand, or a stunted hand, or a withered hand. Were it not that you might become arrogant, I would tell you what Allah has promised, on the tongue of Muhammad ﷺ, to those who kill them."I said, "Did you yourself hear this from Muhammad ﷺ?"He replied, "Yes, by the Lord of the Kaabah. Yes, by the Lord of the Kaabah. Yes, by the Lord of the Kaabah."
ذكر الخوارج، فقال: فيهم رجل مخدج اليد، أو مودن اليد، أو مندون اليد لولا أن تبطروا لحدثتكم بما وعد الله الذين يقتلونهم على لسان محمد ﷺ: قال قلت: آنت سمعته من محمد ﷺ قال: إي ورب الكعبة إي ورب الكعبة، إي ورب الكعبة.
Muslim narrated it in the Book of Zakat (1066:155) through several routes from Hammad bin Zayd and Ismail bin Ulaya, both of them from Ayub, from Muhammad, from Ubayda, from Ali, and he related it.His saying, "withered hand," means a hand that is deficient or small. It is said, wadantu the thing and awdantuhu, meaning I diminished it and made it small. His saying, "stunted hand," means a hand that is small and contracted. Al-mawdun and al-muthdun both mean one who is deficient in physical form.